Nearsighted Vision on the Rise

Have you noticed that more people wear eye­glasses (or contacts) than in the past? That’s largely because myopia—that is, nearsightedness, meaning trouble seeing distant objects—is far more common today than a few decades ago.

This was confirmed by an analysis in the journal Ophthalmology, which included 15 European studies and 62,000 people. Myopia increased from 18 percent in those born between 1910 and 1939 to 24 percent in those born between 1940 and 1979. Even more dra­matic: The researchers found that 47 percent of those ages 25 to 29 have myopia, almost dou­ble the prevalence among those ages 55 to 59 (27 percent).

This is happening around the world. While 25 percent of Americans ages 12 to 54 were nearsighted in 1972, 42 percent were in 2004, according to a study in the Archives of Ophthalmology. Myopia is even more com­mon in Southeast Asia.

The increase in myopia rates may be partly due to more vision testing, but experts now also attribute it to rising levels of education and the close work that entails. For instance, college graduates are twice as likely to be myopic as people their age whose education stopped at primary school, according to the new European analysis. More time reading and working with computers, together with less time spent on outdoor activities, may help explain the correlation between near­sightedness and higher education.

Until about a decade ago, most vision spe­cialists said that close work is only a minor contributor to myopia, citing genetic factors instead. Clearly, myopia runs in families. But how we use our eyes seems to be as impor­tant as our genes when it comes to visual acu­ity. For example, researchers have found that if children of myopic parents spend lots of time outdoors, they’re at only slightly greater risk of becoming nearsighted than children whose parents are not myopic.

More close work, combined with less out­door time, apparently increases the risk of myopia in several ways. Over the years close work can cause elongation of the eye so that light rays from a near object will come into focus more readily. Outdoor activity, in con­trast, allows the eye to focus on distances and thus relax.

Our take: If spending more time on outdoor activi­ties will help young people maintain visual acuity, that’s worth encouraging, especially since it’s healthful in other ways.